1. Field of the Invention
The present invention relates to a lens meter for measuring optical characteristics of a lens for an eye such as a spectacle lens.
2. Description of Related Art
Conventionally, there is known a lens meter which projects a measurement light bundle onto a lens and detects the measurement light bundle transmitted through the lens with a photodetector, then obtains optical characteristics of the lens based on the detected results. Normally, the lens meter of this kind measures optical characteristics of the lens placed on a nosepiece. And, in the case of measuring optical characteristics of a multifocal lens such as a progressive focal lens (referred to as a progressive lens hereinafter), the lens meter detects a far viewing section of the lens and measures optical characteristics thereof, then detects a near viewing section and measures optical characteristics thereof.
Thus, the conventional lens meter needs an operation of seeking optimum measuring points of the far viewing section and the near viewing section while moving the lens on the nosepiece, and the operation is troublesome particularly in the case of the progressive lens. In particular, this is difficult for an unskilled operator, and there are problems in accuracy in measurement and reproducibility.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide a lens meter which can measure optical characteristics of a multifocal lens, particularly a progressive lens easily.
To achieve the objects and in accordance with the purpose of the present invention, as embodied and broadly described herein, a lens meter for measuring optical characteristics of a lens is provided with a first measurement optical system for measuring optical characteristics of a far viewing section of a multifocal lens and a second measurement optical system for measuring optical characteristics of a near viewing section of the multifocal lens. The first measurement optical system has a first measurement optical axis, and the second measurement optical system has a second measurement optical axis which is different from the first measurement optical axis.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.